.. | ||
Google.Authenticator | ||
Google.Authenticator.Tests | ||
Google.Authenticator.WebSample | ||
Google.Authenticator.WinTest | ||
Google.Authenticator.sln | ||
LICENSE | ||
README.md |
GoogleAuthenticator
Simple, easy to use server-side two-factor authentication library for .NET that works with Google Authenticator
Install-Package GoogleAuthenticator
1.x Usage
See blog post for usage instructions (1.x only):
2.x Usage
Additional examples at Google.Authenticator.WinTest and Google.Authenticator.WebSample
using Google.Authenticator;
string key = Guid.NewGuid().ToString().Replace("-", "").Substring(0, 10);
TwoFactorAuthenticator tfa = new TwoFactorAuthenticator();
SetupCode setupInfo = tfa.GenerateSetupCode("Test Two Factor", "user@example.com", key, false, 3);
string qrCodeImageUrl = setupInfo.QrCodeSetupImageUrl;
string manualEntrySetupCode = setupInfo.ManualEntryKey;
imgQrCode.ImageUrl = qrCodeImageUrl;
lblManualSetupCode.Text = manualEntrySetupCode;
// verify
TwoFactorAuthenticator tfa = new TwoFactorAuthenticator();
bool result = tfa.ValidateTwoFactorPIN(key, txtCode.Text)
Common Pitfalls
- Old documentation indicated specifying width and height for the QR code, but changes in QR generation now uses pixels per module (QR "pixel") so using a value too high will result in a huge image that can overrun memory allocations
- Don't use the secret key and
ManualEntryKey
interchangeably.ManualEntryKey
is used to enter into the authenticator app when scanning a QR code is impossible and is derived from the secret key (discussion example)
Notes
On linux, you need to ensure libgdiplus
is installed if you want to generate QR Codes. See https://github.com/codebude/QRCoder/issues/227.